Write access to a variable in a server

Abstract

A method for optimizing repeated write access by a client to at least one variable in a server via OPC UA, wherein a call method for repeated write access is provided on the server, the call method includes notification of an access time interval and at least one variable for the repeated write access, the client calls the call method on the server, the server is notified of an access time interval and the at least one variable for the repeated write access in the process, where the server creates a data structure for the repeated write access and maintains said data structure during the access time interval, values of the at least one variable which are to be written are transmitted to the server by the client during the access time interval, and the server allocates each value transmitted by the client to the associated variable.

The invention claimed is: 
     
       1. A method for optimizing repeated OPC Unified Architecture (OPC-UA) write access by a client to at least one variable in a server via OPC-UA, the method comprising:
 providing a call method for repeated OPC-UA write access on the server, the call method comprising notification of an access time interval and at least one variable for the repeated OPC-UA write access; 
 calling, by the client, the call method on the server and notifying the server of an access time interval and the at least one variable for the repeated OPC-UA write access; 
 creating, by the server, a data structure comprising an OPC-UA subscription for the repeated OPC-UA write access after the call method has been called by the client and maintaining the data structure comprising the OPC-UA subscription during the access time interval; 
 transmitting, by the client, values of the at least one variable which are to be written to the server during the access time interval; and 
 allocating, by the server, each value transmitted by the client to the associated variable via the data structure comprising the OPC-UA subscription. 
 
     
     
       2. The method as claimed in  claim 1 , further comprising:
 deleting the data structure comprising the OPC-UA subscription created by the server after expiry of the access time interval. 
 
     
     
       3. The method as claimed in  claim 1 , wherein the server allocates a unique identification number to the data structure comprising the OPC-UA subscription and the server notifies the client of this identification number. 
     
     
       4. The method as claimed in  claim 1 , wherein the server transmits a write message to the client each time a value of the at least one variable is written to notify the client of the writing of the value. 
     
     
       5. A client for optimizing repeated OPC Unified Architecture (OPC-UA) write access to at least one variable in a server via OPC-UA, wherein the client is configured to call a call method for the repeated OPC-UA write access on the server and therefore to notify the server of an access time interval and the at least one variable for the repeated OPC-UA write access and to transmit values of the at least one variable which are to be written to the server during the access time interval. 
     
     
       6. A server for optimizing repeated OPC Unified Architecture (OPC-UA) write access by a client to at least one variable in the server via OPC-UA, wherein the server is configured to provide a call method for the repeated write access, create a data structure comprising an OPC-UA subscription for the repeated OPC-UA write access after the call method has been called by the client and to maintain said data structure comprising the OPC-UA subscription during an access time interval and to write the values of the at least one variable which are to be written and have been transmitted by the client via data structure comprising the OPC-UA subscription. 
     
     
       7. The server as claimed in  claim 6 , wherein the server is further configured to delete the data structure comprising the OPC-UA subscription created by said server after expiry of the access time interval. 
     
     
       8. The server as claimed in  claim 7 , wherein the server is configured to allocate a unique identification number to the data structure comprising the OPC-UA subscription and to notify the client of this identification number. 
     
     
       9. The server as claimed in  claim 7 , wherein the server is further configured to transmit a write message to the client each time a value of the at least one variable is written to confirm writing of the value to the client. 
     
     
       10. The server as claimed in  claim 6 , wherein the server is configured to allocate a unique identification number to the data structure comprising the OPC-UA subscription and to notify the client of this identification number. 
     
     
       11. The server as claimed in  claim 10 , wherein the server is further configured to transmit a write message to the client each time a value of the at least one variable is written to confirm writing of the value to the client. 
     
     
       12. The server as claimed in  claim 6 , wherein the server is further configured to transmit a write message to the client each time a value of the at least one variable is written to confirm writing of the value to the client. 
     
     
       13. A network optimizing repeated OPC Unified Architecture (OPC-UA) write access by a client to at least one variable in a server via OPC-UA, comprising:
 at least one client configured to call a call method for the repeated OPC-UA write access on the server and therefore to notify the server of an access time interval and the at least one variable for the repeated OPC-UA write access and to transmit values of the at least one variable which are to be written to the server during the access time interval; and 
 at least one server configured to provide a call method for the repeated OPC-UA write access, create a data structure comprising an OPC-UA subscription for the repeated OPC-UA write access after the call method has been called by the client and to maintain said data structure comprising the OPC-UA subscription during an access time interval and to write the values of the at least one variable which are to be written and have been transmitted by the client via the data structure comprising the OPC-UA subscription.